Advocates for expanding access to medical marijuana plan to turn up the pressure on members of Congress who aren't supporting their cause.

They're starting with two House members who voted last week against an amendment to the Commerce-Justice-Science appropriations bill that would bar federal government interference on state-approved pot and hemp laws.

Over the next few days, the "Vote Medical Marijuana" campaign, housed within the medical marijuana advocacy group Americans for Safe Access, will run 30-second TV spots on MSNBC in Maryland and South Florida, the homes of two of the members who voted "no" — Republican Andy Harris and Democrat Debbie Wasserman Schultz.

"Congressman Andy Harris thinks it's OK for medical marijuana patients to go to federal prison, even though Maryland passed a medical marijuana bill in April," a man's voice intones over the first television ad. "On May 30, Congressman Harris voted against an amendment to respect marijuana laws and protect Maryland patients.

"Why would Congressman Harris vote to send patients like this to prison?" the voice continues, as an image of a 4-year-old boy who suffers from epilepsy and his mother is displayed. "Seventy-two percent of Maryland residents support medical marijuana. Is Congressman Harris out of touch with Maryland?"

The ad targeting Wasserman Schultz, one of just 18 Democrats to vote against the amendment and the only member of of leadership to cast a "no" vote, follows a nearly identical framework.

The 30-second spot alleges that Wasserman Schultz wants medical marijuana users to go to federal prison, while 88 percent of Floridians support legalizing access. The same man's voice asks whether Wasserman Schultz is "out of touch" with Florida, and an image flashes across the screen of an elderly man and his wife, who has Amyotrophic Lateral Sclerosis, a fatal neurological disease.

Though only airing in two corners of the country and in response to two members' votes, the ads could soon turn up in more districts, and resonate with other members on both sides of the aisle who voted against the amendment.

Senators could also feel the heat in anticipation of their chamber's consideration of the C-J-S appropriations bills in the weeks ahead.

The Senate appropriations chairwoman and the head of the Senate's C-J-S subcommittee, Democrat Barbara A. Mikulski, hails from Maryland, and said this week that she supports the availability of medical marijuana “under regulation,” but she has not been an active proponent of changing federal policy. Meanwhile, the C-J-S subcommittee ranking member, Richard C. Shelby, R-Ala., has made his opposition to the legalization of marijuana known, "and would therefore oppose such a provision," according to a Senate GOP appropriations aide.

The full Senate appropriations panel held a mark-up of its C-J-S bill on Thursday morning, without including any amendments relating to medical marijuana, though most amendment battles are waged not in committee but on the Senate floor.

But even if the Senate were to agree to the House amendment, or language similar, negotiations between the two chambers to combine the bills might result in the provision being stripped: House Appropriations Chairman Harold Rogers, R-Ky., and C-J-S Chairman Frank R. Wolf, R-Va., are both opposed to medical marijuana.

Every member of House GOP leadership, with the exception of Republican National Campaign Committee Chairman Greg Walden of Oregon, also voted against the House amendment last week.

John Gramlich, Tamar Hallerman and Joanna Anderson contributed to this report.